LASER INTERFEROMETER GRAVITATIONAL WAVE OBSERVATORY

LIGO Laboratory / LIGO Scientific Collaboration

LIGO-E960050-v12 Advanced LIGO 7 May 2013

see DCC record for approval

LIGO Vacuum Compatible Materials List

D. Coyne (ed.)

Distribution of this document:

LIGO Science Collaboration

This is an internal working note

of the LIGO Project.

California Institute of Technology

LIGO Project – MS 18-34

1200 E. California Blvd.

Pasadena, CA 91125

Phone (626) 395-2129

Fax (626) 304-9834

E-mail: info@ligo.caltech.edu

Massachusetts Institute of Technology

LIGO Project – NW17-161

175 Albany St

Cambridge, MA 02139

Phone (617) 253-4824

Fax (617) 253-7014

E-mail: info@ligo.mit.edu

LIGO Hanford Observatory

P.O. Box 1970

Mail Stop S9-02

Richland WA 99352

Phone 509-372-8106

Fax 509-372-8137

LIGO Livingston Observatory

P.O. Box 940

Livingston, LA 70754

Phone 225-686-3100

Fax 225-686-7189

http://www.ligo.caltech.edu/

LIGO LIGO-E960050-v12

2

CHANGE RECORD

Revision Date Authority Description

A 30 Jul 1996 Initial Release Initial Release

B/v1 5 Apr 2004 DCN

E030570-01

Added approved materials for initial LIGO, clarified the

designation "presently used", or "provisional" materials,

added independent approval for Initial LIGO and Advanced

LIGO approval.

v2 9 Sep 2009 See DCC

record

Removed distinction between initial and advanced LIGO

for approval

Made an explicit notation in the materials list if the use

of a material is restricted (or not)

Moved a number of materials from the provisionally

approved to the approved list, although in some cases

with restrictions (e.g. carbon steel, Sm-Co, Nd-Fe-B,

Vac-Seal, copper, Tin-Lead solder, etc.) and removed the

provisional list from the document

Added a number of materials to the approved list,

although in some cases with restrictions (e.g. adhesives,

aluminum bronze, etc.)

Added a few materials to the explicitly excluded list, e.g.

aluminum alloy 7000 series, brass (aka manganese

bronze), free-machining grades of stainless steel (303,

303S, 303Se) except as small fasteners, etc.

Added a number of references

Added a section on general restrictions on materials (e.g.

no castings, material certifications are always required,

only the grades and sources called out for the polymers

are permitted, etc.)

Most outgassing rate values remain blank in the

materials list (pending)

v3 16 Sep 2009 See DCC

record

Added SEI-ISI actuators to approved list

Clarified that no castings refers to metals only

Added exception for the use of grinding to prepare the

leads for in-vacuum photodiodes

Added numbers to the rows of the approved materials list

for easier reference

Added the grade and source for PEEK and carbon-loaded

PEEK

v4 12 Nov 2009 See DCC

record

Explicitly added the Ferritic Stainless Steels (400 series)

to the approved materials list. Of high vapor pressure

elements, these alloys have 0.06% P max and 0.15% S

max, which is well under the 0.5% max allowed in

LIGO-L080072-00 [Ref. b)7]

v5 13 May 2010 See DCC

record

Added permalloy MuMetals (i.e. nickel-iron-

molybdenum alloys) which is an inherently vacuum

compatible material if wrought (not cast)

Clarified that 450G, 450GL, 450CA and 450U grades of

PEEK are all allowable, but restricted (all polymers are

restricted)

Added PEEK ESD 480 (for use as the A-OSEM head)

LIGO LIGO-E960050-v12

3

CHANGE RECORD

Revision Date Authority Description

v6 17 Jun 2010 See DCC

record

Added as an allowable material: Ferro Corporation

porcelain/enamel frit, PE RTU GC Gloss Blk RM108

v7 7 Sep 2010 See DCC

record

Added Tungsten Carbide cermet (aka cemented carbide;

WC-Co or WC-Ni) as an inherently vacuum compatible

material

v8 3 Nov 2010 See DCC

record

Added MasterBond EP30-2 as acceptable adhesive for use in

the following aLIGO applications:

1) bonding suspension wire break-offs (aka stand-offs

or prisms) to masses

2) OSEM magnet assembly

3) OSEM optical filter attachment

4) bonding Acoustic Mode Dampers (AMDs) to test

mass barrel

5) bonding earthquake stops to the compensation plate

Use for any other application in aLIGO must be reviewed

and approved by Systems.

v9 4 Nov 2010 See DCC

record

Added all martensitic 400 series stainless steels, except AISI

grade 416 (which has high sulfur content). Grade 416 was

added to the explicitly excluded list.

v10 11 Jul 2011 See DCC

record

Added Schott KG5 (and similar) filter glass for use by ISC in

low to moderate power applications

v11 27 Dec 2011 See DCC

record Added 301 stainless steel to the acceptable materials list

V12 7 May 2013 See DCC

record

Added Epoxy Pak EP-1730-1 as an acceptable, though

restricted, epoxy for use in aLIGO cabling

LIGO LIGO-E960050-v12

4

TABLE OF CONTENTS

1 Introduction ................................................................................................................................ 5

2 Scope ........................................................................................................................................... 5

3 Nomenclature and Acronyms .................................................................................................... 5

4 Ultra-High Vacuum Material Concerns ................................................................................... 6

5 Vacuum Requirements ............................................................................................................... 6

6 Procedure for Qualifying New Materials .................................................................................. 7

7 VRB wiki Log ............................................................................................................................. 7

8 General Restrictions ................................................................................................................... 7

9 Approved Materials .................................................................................................................... 8

10 Explicitly Rejected Materials ................................................................................................... 23

11 References for the approved materials table ........................................................................... 23

LIST OF TABLES

Table 1: Approved Construction Materials ........................................................................................ 9

LIGO LIGO-E960050-v12

5

1 Introduction

All items to be installed inside LIGO Observatory vacuum systems must be on the "approved

materials" list (components and materials).

2 Scope

The materials listed herein are those which are intended for use in vacuum. Materials used for

items which are temporarily inside a LIGO vacuum system, but do not reside in vacuum (e.g.

alignment fixtures, installation tooling, etc.) are not restricted to this material list. These items

(referred to as "Class B"1 as opposed to "Class A" items which remain in the vacuum system) must

comply with LIGO cleanliness standards and must not leave residues of non-vacuum compatible

materials (e.g. hydrocarbon lubricants).

3 Nomenclature and Acronyms

AdL Advanced LIGO

ADP Ammonium Di-hydrogen Phosphate [(NH4)H2PO4]

AES Auger Electron Spectroscopy

AMU Atomic Mass Unit

FTIR Fourier Transform Infrared Spectroscopy

HC Hydrocarbons

InL Initial LIGO

KDP Potassium Di-hydrogen Phosphate [KH2PO4]

LIGO Laser Interferometer Gravitational Wave Observatory

OFHC Oxygen Free High-Conductivity Copper

NEO Neodymium Iron Boron

PFA Perfluoroalkoxy fluoropolymer (Du Pont)

PTFE Polytetrafluorethylene (Du Pont)

PZT Lead-Zirconate-Titanate

RTV Room Temperature Vulconizing Silicone elastomer

SIMS Stimulated Ion Mass Spectroscopy

UHV Ultra High Vacuum

VRB LIGO Vacuum Review Board

XPS X-ray Photoelectric Spectroscopy

1 Betsy Bland (ed.), LIGO Contamination Control Plan, LIGO-E0900047

LIGO LIGO-E960050-v12

6

4 Ultra-High Vacuum Material Concerns

There are two principal concerns associated with outgassing of materials in the LIGO vacuum

system:

a) Outgassing increases the gas load (and column density) in the system and consequently may

either compromise the interferometer phase noise budget or require higher pumping

capacity. Reduction with time, whether 1/t (range of adsorption energies) or 1/sqrt(t)

(diffusion followed by desorption) is important and the particular gas species (whether

condensable or non-condensable) is critical. Even inherently compatible, low outgassing

materials (e.g. 6061 aluminum alloy) will contribute to the gas load (especially if not

properly cleaned and/or copious amounts are installed into the vacuum system). However,

the most significant risk is likely to be from materials which have inherently high

outgassing rates (e.g. water outgassing from flouroelastomers such as Viton® and

Flourel®).

The literature is most useful in providing total and water outgassing rates. Since in LIGO,

there is a special problem of larger phase noise sensitivity to (and concern of optical

contamination from) heavy hydrocarbons, where possible, the hydrocarbon outgassing or

surface contamination information should be provided.

b) Outgassing is a potential source of contamination on the optics with the result of increased

optical losses (scatter and absorption) and ultimately failure due to heating. The amount of

outgassing is less important than the molecular species that is outgassed. Little is known of

the most important contamination sources or the mechanisms that lead to the optical loss

(e.g., UV from second harmonic generation, double photon absorption photoeffect, simple

molecular decomposition in the optical fields leaving an absorbing residue, etc.).

In the approved materials list, one column entry indicates whether the listed material has the

potential for (is suspected of) being a significant contributor as regards a) or b) or both.

5 Vacuum Requirements

An allocation of high molecular weight hydrocarbon outgassing budget to assemblies within the

AdL UHV is given in LIGO-T0400012. However, this document is in need of revision (a) to reflect

the pumping capacity of the beam tube (which reduces the requirements considerably), and (b) to

more accurately reflect the evolved AdL configuration.

An allocation of total gas load for AdL has not been made as yet. With the elimination of the

significant amount of Flourel® flouroelastomer in InL (spring seats, parts of the InL seismic

isolation system), the water load will decrease dramatically. However, recent calculations3 of test

mass damping due to residual gas suggest that this may not be sufficient. We will need to achieve a

total pressure of 10-9 torr or less in proximity to each test mass. A total gas load budget/estimate

will be created.

The limits on optical loss due contamination are < 1 ppm/yr absorption and < 4 ppm/yr scatter loss

2 D. Coyne, Vacuum Hydrocarbon Outgassing Requirements, LIGO-T040001

3 N. Robertson, J. Hough, Gas Damping in Advanced LIGO Suspensions, LIGO-T0900416-v1

LIGO LIGO-E960050-v12

7

for any test mass (TM), high reflectance (HR), surface4.

6 Procedure for Qualifying New Materials

A request to qualify a new material or component/assembly should be addressed to the LIGO Chief

Engineer or the LIGO Vacuum Review Board with a justification regarding the need for the new

material and an estimate of the amount of material required. Materials can only be added to the

"approved" list after extensive testing in accordance with the document "LIGO Vacuum

Compatibility, Cleaning Methods and Procedures"5.

7 VRB wiki Log

This revision captures all relevant LIGO Vacuum Review Board (VRB) decisions as of the date of

this release. For more recent direction not yet captured in a revision of this document, see the LIGO

VRB wiki log (access restricted to LSC members).

8 General Restrictions

1) Material certifications are required in every case.

2) Only the grades called out

3) Only the grades and sources called out for the polymers (unless otherwise noted).

4) All polymers are restricted (even if approved). The use of an approved polymer in a new

application must be approved. Despite the fact that some polymer materials are approved

for use, these materials should be avoided if possible and used sparingly, especially if used

in proximity to LIGO optics.

5) Special precautions must be taken for adhesives. Often the shelf life for adhesives is

limited. All adhesives should be degassed as part of the preparation procedure. Extreme

care must be taken when mixing multi-part adhesives, to insure that the proper ratio is used

and accurately controlled.

6) No metal castings, including no aluminum tooling plate.

7) All surfaces are to be smooth (preferably ≤ 32 micro inches Ra). All metal surfaces are

ideally machined.

8) All machining fluids must be fully synthetic (water soluble, not simply water miscible) and

free of sulfur, chlorine, and silicone.

9) No bead or sand blasting is permitted.

4 G. Billingsley et. al., Core Optics Components Design Requirements Document, section 4.2.2.6 of LIGO-T080026-

00. The timescale for accumulation (i.e. the time span between in situ re-cleaning of the test mass optics) has been

chosen here to be 1 year. It is possible that a somewhat shorter time span could be accommodated.

5 D. Coyne (ed.), LIGO Vacuum Compatibility, Cleaning Methods and Qualification Procedures, LIGO-E960022

LIGO LIGO-E960050-v12

8

10) No grinding is permitted (due to potential contamination from the grinding wheel matrix),

except for (a) grinding maraging steel blades to thickness6 and (b) photodiode lead end

preparation for pin sockets.

11) Parts should be designed and fabricated to provide venting for enclosed volumes

12) For design applications where dimensional control is extremely important or tolerances are

exceedingly tight, it is the responsibility of the design engineer to (a) establish a basis for

baking parts at temperatures lower than the default temperatures (defined in LIGO-

E960022), and (b) get a waiver for a lower temperature bake from the LIGO Vacuum

Review Board.

13) All materials must be cleaned with appropriate chemicals and procedures (defined in LIGO-

E960022) and subsequently baked at “high temperature”. The appropriate temperature is

defined in LIGO-E960022. Typical hold duration at temperature is 24 hours. The preferred

bake is in a vacuum oven so that the outgassing rate can be shown to be acceptable by

Residual Gas Assay (RGA) measurement with a mass spectrometer. If the part is too large

to be placed in a vacuum oven, then it is air baked (or dry nitrogen baked) and then its

surface cleanliness is established by FTIR measurement.

14) Welding, brazing, soldering have special restrictions and requirements7 defined in LIGO-

E0900048.

15) For commercially produced components with potentially many materials used in the

construction, a detailed accounting of all of the materials and the amounts used must be

submitted for review. It may be necessary for some components to get certifications (per

article or serial number) of the materials employed in their manufacture, so that material

substitutions by the manufacturer are visible to LIGO.

9 Approved Materials

The following Table lists materials which are approved for use in all LIGO vacuum systems. In

many cases the materials are restricted to a particular application. Use of the material for another

application must be approved by either the LIGO Chief Engineer or the LIGO Vacuum Review

Board. References for the approved materials list table are given in the last section.

6 C. Torrie et. al., Manufacturing Process for Cantilever Spring Blades for Advanced LIGO, LIGO-E0900023

7 C. Torrie, D. Coyne, Welding Specification for Weldments used within the Advanced LIGO Vacuum System, LIGO-

E0900048

LIGO LIGO-E960050-v12

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Table 1: Approved Construction Materials

# Material

Un

rest

ric

ted

R

estr

icte

d

Specific

Restrictions

Reference Outgassing Data8 (torr-liter/s/cm2)

refe

ren

ces

Co

nd

itio

n

JT

ota

l

Jw

ate

r

JH

2

JH

C

a)

ga

s

b)

con

tam

.

Adhesives

A1 hydroxy-catalysis, silicate bonding*

for bonding highly flat, fused silica

components together

A2 Obsolete: Vac-Seal epoxy

Manufactured by Tra-Con9 and

distributed by Physical Electronics and

later Gamma Vacuum.

for use in bonding to optics a, b

A3 Epoxy Tra-Bond #2151 (thermally

conductive, electrically insulating, low

outgassing), from Tra-Con, Inc.

ADE capacitive position sensors for the

seismic system only

a, b

A4 Obsolete: Epoxy Tra-Bond #2254, from

Tra-Con, Inc. No longer manufactured

Used for prototype ADE capacitive

sensors (~2004)

a, b

A5 Epoxy Tra-Duct #2902 Epoxy

(electrically conductive, silver epoxy, low

outgassing), from Tra-Con, Inc.

ADE capacitive position sensors for the

seismic system only

a, b

A6 Obsolete: Epoxy Tra-Duct #2903

(conducting), from Tra-Con, Inc. No

longer manufactured

Used for prototype ADE capacitive

sensors (~2004)

a, b

8 The outgassing rate entries in the table are representative of material sample measurements and provided as a design guideline for working up a gas budget in the

vacuum system.

9 Apparently as of March 2008, the Vac-Seal product is no longer available. In previous versions of this document it was (erroneously?) reported that VacSeal was

manufactured by Perkin Elmer. It appears to have been manufactured by Tra-Con, now part of Emerson & Cuming, a division of Henkel. There is another product

called Vacseal from SPI, which we have not qualified for use.

LIGO LIGO-E960050-v12

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# Material

Un

rest

ric

ted

R

estr

icte

d

Specific

Restrictions

Reference Outgassing Data8 (torr-liter/s/cm2)

refe

ren

ces

Co

nd

itio

n

JT

ota

l

Jw

ate

r

JH

2

JH

C

a)

ga

s

b)

con

tam

.

A7 Obsolete: Epoxy Tra-Bond 2103

(a medium viscosity, low outgassing,

general purpose epoxy). No longer

manufactured.

Used for prototype ADE capacitive

sensors (~2004)

a, b

A8 Polyimide Dupont PI-2525

(Can only be used in thin films, e.g. for

potting coils.)

PSI actuator coils for the seismic isolation

system only

a, b

A9 Polyimide Cycom 3001 and 3002,

manufacureed by Cytec Engineered

Materials Inc.

(Can only be used in thin films, e.g. for

potting coils.)

[N.B.: apparently no longer

manufactured.]

Used in prototype PSI actuator coils for

the seismic isolation system only

a, b

A10 Ceramabond #835M

& 571 (inorganic, ceramic cements)

used for bonding wire and alumina circuit

boards into the Initial LIGO suspension

OSEM assembly

A11 Electronic Materials Inc.'s Optocast

3553LV-UTF-HM

(A Low Viscosity, Ultra Thin Film epoxy

with Heat Mechanism. The

assembly/cure procedure includes both a

UV binding step and a 120 degree cure

for 24 hours.)

Bonding fused silica optical elements to a

fused silica base plate for a semi-

monolithic assembly, for use in the

Output Mode Cleaner (OMC)

a, b

LIGO LIGO-E960050-v12

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# Material

Un

rest

ric

ted

R

estr

icte

d

Specific

Restrictions

Reference Outgassing Data8 (torr-liter/s/cm2)

refe

ren

ces

Co

nd

itio

n

JT

ota

l

Jw

ate

r

JH

2

JH

C

a)

ga

s

b)

con

tam

.

A12 MasterBond EP30-2 Restricted to the following applications:

1) bonding suspension wire break-offs

(aka stand-offs or prisms) to masses

2) OSEM magnet assembly

3) OSEM optical filter attachment

4) bonding Acoustic Mode Dampers

(AMDs) to test mass barrel

5) bonding earthquake stops to the

compensation plate

5.6e-11 2.2e-12 1.2e-12 5.0e-13 a, b 23,24

A13 Epoxy Pak Ep-1730-1 Restricted to the following applications:

Connector potting

26

Ceramics & Cermets

B1 Fired nonpermeable ceramics

(e.g. alumina, beryllia)*

---- ---- ---- ---- ----

B2 Boron Nitride (machinable)* ---- ---- ---- ---- ----

B3 Macor (a machinable ceramic made by

Corning)*

---- ---- ---- ---- ----

B4 Clayless Black Enamel, Ferro Corp. L.O.,

34792

Fired onto prototype stainless steel baffles

for the Beam Tube (not used in

installation)

Stressed

& baked

7.3e-13 5.0e-15 6.9e-13 1.2e-16 a 21

B5 Glazed Ceramics (e.g., Porcelain) Unbaked 1E-8 1E-8 ---- 1,4

LIGO LIGO-E960050-v12

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# Material

Un

rest

ric

ted

R

estr

icte

d

Specific

Restrictions

Reference Outgassing Data8 (torr-liter/s/cm2)

refe

ren

ces

Co

nd

itio

n

JT

ota

l

Jw

ate

r

JH

2

JH

C

a)

ga

s

b)

con

tam

.

B6 Tungsten Carbide cermet (aka cemented

carbide)*

(WC-Co or WC-Ni)

22

Coatings/Platings

C1 flame-sprayed Aluminum-oxide (white) Used as a high emissivity coating for in-

vacuum thermal management of the ISC

photodiode pre-amp assembly

C2 flame-sprayed 80% Aluminum Nitride,

20% Aluminum Oxide (grey)

Used as a high emissivity coating for in-

vacuum thermal management of the ISC

photodiode pre-amp assembly

C3 Electroless nickel plating Low phosphorous plating; see

specification in reference 11

---- ---- ---- ---- a, b 10,11

C4 Silver* Used on fasteners in stainless steel a, b

C5 Titanium-Nitride

Magnaplate Corp., PVD TiN coating,

Magnagold

Used on several of the InL seismic

isolation system parts

Crystalline Materials

D1 ADP (Ammonium Di-hydrogen

Phosphate [(NH4)H2PO4])*

---- ---- ---- ---- ----

D2 Calcite* ---- ---- ---- ---- ----

D3 Diamond* ---- ---- ---- ---- ----

D4 Germanium* ---- ---- ---- ---- ----

D5 KDP (Potassium Di-hydrogen Phosphate

[KH2PO4])*

---- ---- ---- ---- ----

D6 Quartz* ---- ---- ---- ---- ----

D7 Sapphire* ---- ---- ---- ---- ----

LIGO LIGO-E960050-v12

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# Material

Un

rest

ric

ted

R

estr

icte

d

Specific

Restrictions

Reference Outgassing Data8 (torr-liter/s/cm2)

refe

ren

ces

Co

nd

itio

n

JT

ota

l

Jw

ate

r

JH

2

JH

C

a)

ga

s

b)

con

tam

.

D8 Silicon Dioxide* ---- ---- ---- ---- ----

D9 Tantalum Pentoxide (hard optical

coating) (including Titanium dopes

Ta2O5)*

---- ---- ---- ---- ----

D10 Zinc Selenide, ZnSe* Used in viewports for 10.6 micron

wavelength transmission

Electronic Components

E1 OSEM Assembly

(Adv. LIGO Optical Sensor and Electro-

Magnetic actuator), D#?

Material composition list is given in

REF?

Used in the InL suspension systems a, b

E2 AOSEM Assembly

(Adv. LIGO Optical Sensor and Electro-

Magnetic actuator), D#pending; see

T0900286 and related documents

Material composition list is given in

REF# pending

Used in the AdL suspension systems a, b

E3 BOSEM Assembly

(Birmingham Optical Sensor and Electro-

Magnetic actuator), D#?

Material composition list is given in

E040373-00

Used in AdL suspension systems a, b

LIGO LIGO-E960050-v12

14

# Material

Un

rest

ric

ted

R

estr

icte

d

Specific

Restrictions

Reference Outgassing Data8 (torr-liter/s/cm2)

refe

ren

ces

Co

nd

itio

n

JT

ota

l

Jw

ate

r

JH

2

JH

C

a)

ga

s

b)

con

tam

.

E4 Electro-Magnetic Actuators, SEI-ISI,

manufactured by PSI, model nos. ? and ?

comprised of:

SmCo magnets

stainless steel housing

PEEK terminal block (Accu-Glass

Products Inc. part # PEEK-TB-2P)

Coil wire ?

Coil potting adhesive: Polyimide Dupont

PI-2525

For use in the SEI-ISI subsystems only

E5 Connector: Glenair Micro-D (no

interfacial seal with nickel or gold

plating):

9-pin micro-D PCB (Right Angled)

connector

9-pin micro-D Solder (Straight) connector

[materials composition list]

Used in the suspension BOSEM assembly

(OSEM coilformer and mating

connectror)

a, b

LIGO LIGO-E960050-v12

15

# Material

Un

rest

ric

ted

R

estr

icte

d

Specific

Restrictions

Reference Outgassing Data8 (torr-liter/s/cm2)

refe

ren

ces

Co

nd

itio

n

JT

ota

l

Jw

ate

r

JH

2

JH

C

a)

ga

s

b)

con

tam

.

E6 Cable: Acu-Glass ribbon cabling

procured through MDC Vacuum Products

Corp. as P/N 680535-1000. KAP-R25-

300SC2

Kapton wire insulation:

1) Kapton film (spiral wrapped around

conductor, 50% overlap): DuPont film,

FM616

2) Overcoat (conformal coating):

polyimide dispersant (liquid resin): Imitec

P/N 201A, with additives (proprietary

additives to aid drying, etc.); this material

is in compliance with mil spec MIL-W-

81381

Connector: Accu-Glass Part #, PEEK

Used for power and signal cabling for the

seismic isolation system and its active

payload elements

a, b

E7 Emitter: Optek OP232 Used in the BOSEM assembly, D060218-

C

a, b

E8 Emitter: Surface Mount LED, Honeywell

P/N SME-2470-001

used in the second (surface mount)

versions of the Initial LIGO OSEM

assembly, D000180-A (short) and

D000069-A (long)

a, b

E9 Emitter: LED TLN107A, Toshiba Used in the first version of the Initial

LIGO OSEM, D960138-02

a, b

E10 Receiver: Centronics BPX65 Used in the BOSEM assembly, D060218-

C

a, b

E11 Receiver: Surface Mount Photodiode,

Honeywell P/N SMD-2420-001

used in the second (surface mount)

versions of the Initial LIGO OSEM

assembly, D000180-A (short) and

D000069-A (long)

a, b

LIGO LIGO-E960050-v12

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# Material

Un

rest

ric

ted

R

estr

icte

d

Specific

Restrictions

Reference Outgassing Data8 (torr-liter/s/cm2)

refe

ren

ces

Co

nd

itio

n

JT

ota

l

Jw

ate

r

JH

2

JH

C

a)

ga

s

b)

con

tam

.

E12 Receiver: Photodiode TPS703A, Toshiba Used in the first version of the Initial

LIGO OSEM, D960138-02

a, b

E13 Flexible Circuit: DuPont Pyralux®

Flexible Circuit, comprised of:

(a) Pyralux ®LF Copper-Clad

Laminate,which is a Kapton®

(polyimide) film bonded to a copper foil

with a C-staged modified acrylic

adhesive, and

(b) Pyralux® coverlay composite are

constructed of Kapton® polyimide film,

coated on one side with a proprietary B-

staged modified acrylic adhesive

Used in the suspension BOSEM

assembly, D050435-C

a, b

E14 Capacitive Position Sensor, ADE

Technologies Inc., Model Nos. 2820-V,

2821-V, 2822-V Vacuum Prepared Probe

[material composition list is proprietary]

Used in the seismic isolation systems for

HAM and BSC chambers

a, b

E15 MWS Wire Industries 32HML (heavy),

or 32QML (quad-build) Kapton insulated

copper wire (32 gauge) with a thick

coating of polyimide-ML

Used for OSEM, AOSEM and BOSEM

voice coil actuators.

a, b

E16 Teflon (FEP) insulated, coaxial, shielded,

silver-plated copper wire, Cooner Wire

Inc., Part# CW2040-3650 F

For the Electro-Static Driver (ESD)

assembly of the Input and End Test Mass

suspensions

a, b

E17 Teflon insulated wire, Cooner Wire, P/N

CZ1104 and P/N CZ1105

used for OSEM cabling, e.g. LIGO-

D990676-C

a, b

E18 Vacuum Feedthroughs, Glass & Ceramic,

manufactured by ISI or Ceramaseal with

Kovar glass to metal seals

LIGO LIGO-E960050-v12

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# Material

Un

rest

ric

ted

R

estr

icte

d

Specific

Restrictions

Reference Outgassing Data8 (torr-liter/s/cm2)

refe

ren

ces

Co

nd

itio

n

JT

ota

l

Jw

ate

r

JH

2

JH

C

a)

ga

s

b)

con

tam

.

Glasses

F1 Corning 7056 or Kodial glass Used in viewport assemblies

F2 Filter Glass, ionically colored

(e.g. Schott KG5 or similar)

For use by ISC in low to moderate power

applications

F3 Fused quartz*

Fused silica*

---- ---- ---- ---- ----

F4 Pyrex glass* unbaked 1.6E-10 1.6E-10 ---- 2

F5 Glass (non-leaded)* unbaked 1E-8 1E-8 ---- 4

F6 Black Glass, shade 12/14 Welders* used for beam dumps

Lubricants

G1 Molybdenum disulfide (MoS2)* Limited to applications where generated

particulates can’t migrate

Metals

H1 Aluminum and Aluminum alloys:

2000 series

4000 series

5000 series

6000 series

(e.g. 6061, 4043, 5052, 2024)

[N.B.: Not the 7000 series]

Wrought form (not a casting). Cast

tooling plate is not acceptable.

unbaked 7.6E-9 7.6E-9 ---- 1,8

H2 Aluminum bronze Some aluminum bronze alloys include

high vapor pressure elements such as zinc

(Zn), phosphorous (P) and lead (Pb).

These alloys must comply with the limits

established in L080072-00; Most alloys

should comply

a 6,7

H3 Beryllium copper* Wrought form (not a casting) ---- ---- ---- ---- 6

LIGO LIGO-E960050-v12

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# Material

Un

rest

ric

ted

R

estr

icte

d

Specific

Restrictions

Reference Outgassing Data8 (torr-liter/s/cm2)

refe

ren

ces

Co

nd

itio

n

JT

ota

l

Jw

ate

r

JH

2

JH

C

a)

ga

s

b)

con

tam

.

H4 Carbon Steel Minimize carbon steel use due to

concerns regarding particulate

contamination from oxidation. Approved

use is for:

(a) high tensile strength suspension wire

(per ASTM A 228/A 228M),

(b) hardended small steel balls and

contact plates in quasi-kinematic mounts,

(c) small disc for magnet attachment for

voice coil actuator on suspension

assemblies

18

H5 Copper-nickel alloys* ---- ---- ---- ---- 6

H6 Copper (elemental and OFHC)* unbaked 4.2E-9 4.2E-9 ---- 2,6

H7 Gold* ---- ---- ---- ---- ----

H8 Indium* ---- ---- ---- ---- ----

H9 Invar™ 36*, Nickel-Iron alloys

H10 Maraging Steel (c-250, Marval 18, c-

300)*

Should be electroless nickel plated (see

restrictions on plating in this table) to

minimize corrosion. Limited to spring

and flexure applications in seismic and

suspension systems.

20

H11 Molybdenum* unbaked 6.8E-7 6.8E-7 ---- 3

H12 MuMetal if a permalloy, i.e. a nickel-

iron-molybdenum alloy

Must comply with ASTM A-753

H13 Neodymium-Iron-Boron (Nd-Fe-B)

Magnets (NEO-35)

H14 Nichrome (Nickel-Chromium) wire*

H15 Niobium* ---- ---- ---- ---- ----

LIGO LIGO-E960050-v12

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# Material

Un

rest

ric

ted

R

estr

icte

d

Specific

Restrictions

Reference Outgassing Data8 (torr-liter/s/cm2)

refe

ren

ces

Co

nd

itio

n

JT

ota

l

Jw

ate

r

JH

2

JH

C

a)

ga

s

b)

con

tam

.

H16 Phosphor bronze Phosphor-Bronze alloys with P <= 0.35

%, Pb <= 1%, Zn <= 1% are acceptable

for UHV service at 1 m or more from any

optics, when the surface area is limited to

~1000 cm2 with sufficient justification

(i.e. no reasonable alternate

materials/parts). However these parts

must be air baked (not vacuum baked)

and require FTIR (not RGA)

qualification.

---- ---- ---- ---- a 6

H17 Platinum* ---- ---- ---- ---- ----

H18 Samarium-Cobalt (Sm-Co) permanent

magnets

19

H19 Silver* unbaked 6E-7 6E-7 ---- 3

H20 Silver solder* ---- ---- ---- ---- ----

H21 Stainless Steels:*

18-8

17-4PH

301

302

304, 304L, 304LN

316, 316L, 316LN

317, 317L

409, 430, 434, 439 (ferritic)

403, 410, 420, 440 (martensitic)

A286 (iron-based "super alloy", similar in

composition to Stainless Steels)

Nitronic 60

unbaked 1.8E-8

(304,

304L)

1.8E-8

(304,

304L)

---- 1

H22 Stainless Steels, free machining grades:

303, 303S, 303Se

Only acceptable for small hardware items

(e.g. nuts, bolts, washers)

a 9

LIGO LIGO-E960050-v12

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# Material

Un

rest

ric

ted

R

estr

icte

d

Specific

Restrictions

Reference Outgassing Data8 (torr-liter/s/cm2)

refe

ren

ces

Co

nd

itio

n

JT

ota

l

Jw

ate

r

JH

2

JH

C

a)

ga

s

b)

con

tam

.

H23 Tin-Lead Solder grade Sn63Pb37, Kester

6337

Restricted to electrical conductor

applications and with minimal amount

due to lead content. Crimped pin

connections are preferred. Rosinless core

only.

a, b

H24 Titanium* ---- ---- ---- ---- ----

H25 Tungsten* unbaked 1.95E-7 1.95E-7 ---- 3

Polymers

I1 PEEK (grade unknown), cable &

connector parts

(1) Adv. LIGO: Electro-Static Drive

(ESD) coaxial cable assembly (cable

adaptor sleeve, part of Accu-Glass

coaxial connector part #100909)

(2) Adv. LIGO: Power and Signal cables

for SEI and payload elements on Optics

Tables (Accu-Glass D-25 connectors, part

#?)

(3) In Initial LIGO, threads used for tying

together the Accu-Glass Kapton-insulated

ribbon cabling (part #?)

(4) PEEK thread woven into the ribbon

cabling in the Acu-Glass in-vacuum

cabling for InL, procured through MDC

Vacuum Products Corp. as P/N 680535-

1000. KAP-R25-300SC2

a, b

I2 PEEK: Victrex grade TDS-450CA30,

Carbon Fiber Loaded.

This material is used to form the abrasion

and dielectric covering used on in-

vacuum cables for AdL

LIGO LIGO-E960050-v12

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# Material

Un

rest

ric

ted

R

estr

icte

d

Specific

Restrictions

Reference Outgassing Data8 (torr-liter/s/cm2)

refe

ren

ces

Co

nd

itio

n

JT

ota

l

Jw

ate

r

JH

2

JH

C

a)

ga

s

b)

con

tam

.

I3 PEEK: Victrex grade TDS-450G. This is a general purpose, machinable or

moldable, version of basic PEEK used to

make connector bodies and cable clamps,

e.g. Adv. LIGO: cable clamps,

D0900004-v1

I4 PEEK: Victrex grade 450G, 450GL,

450CA and 450U

Used for adjuster mechanism on the

BOSEM assembly

a, b

I5 PEEK: Grade 450CA30 from Boedeker

Plastics, 30% Carbon Loaded, virgin

PEEK resin, no other additives

Restricted to use for the body of the

AOSEM assembly, D0901048

a, b

I6 PEEK: Semitron ESd 480 from Boedeker

Plastics, a static dissipative reinforced

PEEK

A-OSEM head Cleaned,

baked

7.2e-12 3.5e-13 8.9e-14 1.8e-13 a, b 25

I7 Teflon PFA-440HP (Dupont) In initial LIGO used for the custom

connector pin-plates on the suspension

cable and on the OSEM head. For Adv.

LIGO used for AOSEM and BOSEM

assemblies.

a, b

I8 Viton or Flourel o-rings, commercial off

the shelf, manufactured by Dupont, 3M,

Parker or Parco

Restricted to o-ring cross sections ≤ 0.275

inch diameter.. For O-rings of less than 8

inches in diameter processing shall be as

called out in E960022. The large diameter

o-rings used for vacuum chamber seals

and large quantities of smaller o-rings

may be processed according to E960159-

01.

a, b 12,13,

14

I9 3M/Dyneon Fluorel FC2180 (or FE5641)

as processed per LIGO-E970130-A

Used for Initial LIGO seismic isolation

system coil spring seats; Initial LIGO

cable clamp liners; Initial LIGO

earthquake stops

unbaked

baked

8.8E-13

1.9E-13

a, b 5,15

LIGO LIGO-E960050-v12

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# Material

Un

rest

ric

ted

R

estr

icte

d

Specific

Restrictions

Reference Outgassing Data8 (torr-liter/s/cm2)

refe

ren

ces

Co

nd

itio

n

JT

ota

l

Jw

ate

r

JH

2

JH

C

a)

ga

s

b)

con

tam

.

I10 3M Fluorel V747-75 as specified in

LIGO-C990061-00

[used for LLO mid-point gate valve o-

rings]

a, b 16

I11 Dupont Viton E-60C as specified per

LIGO-E960085-06

[used for vacuum equipment o-ring seals] a, b 17

I12 Dupont Viton A500 as specified per

LIGO-C961792-06 (also known as

E960085-06)

[used for vacuum equipment o-ring seals] a, b 17

* Denotes materials which, although not tested by LIGO, are intrinsically Ultra High Vacuum (UHV) compatible and are used in UHV practices. Many

of these items, if used at all, will be used in “trace” quantities.

LIGO LIGO-E960050-v12

23

10 Explicitly Rejected Materials

1) Alkali metals

2) Aluminum alloy 7000 series: due to the high zinc content

3) Brass (aka manganese bronze): due to high zinc content

4) Cadmium or zinc plating on metal parts: Cadmium and zinc have prohibitively high vapour

pressures. Crystalline whiskers grow on cadmium, can cause short circuits.

5) Delrin™ or similar polyacetal resin plastics: Outgassing products known to contaminate

mirrors.

6) Dyes

7) Epoxy Tra-Bond 2101: outgassing was measured by LIGO to be too high (note that this is

not a low outgassing epoxy formulation)

8) Inks

9) Manganese bronze (aka brass): due to high zinc content

10) Oils and greases for lubrication

11) Oilite™ or other lubricant-impregnated bearings

12) Oriel MotorMike™ actuators filled with hydrocarbon oil, not cleanable

13) Palladium

14) Soldering flux

15) Stainless Steel, free-machining grades (303, 303S, 303Se, 416): allowable only as small

hardware components (nuts, bolts, washers), due to high sulfur or selenium content

16) RTV Type 615

17) Tellurium

11 References for the approved materials table

1. Dayton, B.B. (1960) Trans. 6th Nat. Vacuum Congress; p 101

2. Schram, A. (1963) Le Vide, No 103, p 55

3. Holland, Steckelmacher, Yarwood (1974) Vacuum Manual

4. Lewin, G. (1965) Fundamentals of Vacuum Science and Technology, p 72

5. Coyne, D., Viton Spring Seat Vacuum Bake Qualification, LIGO-T970168-00, 10 Oct 1997.

6. Coyne, D., Allowable Bake Temperature for UHV Processing of Copper Alloys, LIGO-

T0900368-v2, 11 Aug 2009.

7. Worden, J., Limits to high vapor pressure elements in alloys, LIGO- L080072-00, 12 Sep 2008.

8. Coyne, D., VRB Response to L070131-00: Unacceptability of 7075 Aluminum Alloy in the

LIGO UHV?,LIGO-, LIGO-L070132-00, 11 Nov 2008.

LIGO LIGO-E960050-v12

24

9. Worden, J., VRB response to L080042-00, Is 303 stainless steel acceptable in the LIGO

Vacuum system?, LIGO-L080044-v1, 12 Jan 2009.

10. Worden, J., VRB response to nickel-phosphorous plating issues , LIGO-L0900024-v1, 20 Feb

2009.

11. Torrie, C. et. al., Manufacturing Process for Cantilever Spring Blades for Advanced LIGO,

LIGO-E0900023-v6, 23 Jun 2009.

12. Worden, J., VRB Response to Flourel/Viton O-ring questions, LIGO-L070086-00, 12 Oct

2007.

13. Coyne, D. (ed), LIGO Vacuum Compatibility, Cleaning Methods and Qualification Procedures,

LIGO- E960022

14. Process Systems International, Inc., Specification for Viton Vacuum Bakeout, LIGO Vacuum

Equipment - Hanford and Livingston, LIGO- E960159-v1, 18 Dec 1996.

15. Coyne, D., Component Specification: Material, Process, Handling and Shipping Specification

for Fluorel Parts, LIGO-E970130-A, 17 Nov 1997.

16. Process Systems International, Inc., WA Site GNB Valve Modification Report Update (PSI

V049-1-185) and LA Mid Point Valve O-Ring Specification, LIGO-C990061-00, 21 Jan 1999.

17. Process Systems International, Inc., Vacuum Equipment: O Ring Specification, Rev. 06, LIGO-

E960085-06, 7 Jan 1997.

18. ASTM, Standard Specification for Steel Wire, Music Spring Quality, A 228/A 228M – 07.

19. Worden, J., Re: L0900002-v1: VRB request: all SmCo magnets UHV compatible?, LIGO-

L0900011-v1, 3 Feb 2009.

20. C. Torrie, et. al., Summary of Maraging Steel used in Advanced LIGO, LIGO-T0900091

21. B. Taylor, D. Coyne, Material Qualification RGA Test Results: Ferro Corporation RM108 Frit,

LIGO-E1000221-v1

22. General Carbide Corp., “The Designer’s Guide to Tungsten Carbide”, Aug 2007.

23. B. Taylor, D. Coyne, “Material Qualification RGA Test Results: MasterBond EP30-2 epoxy”,

LIGO-E1000386-v1

24. B. Taylor, D. Coyne, “Optical Contamination Test Results MasterBond EP30-2 samples on

glass slides”, LIGO-E1000479-v1

25. B. Taylor, D. Coyne, “Material Qualification RGA Test Results: Semitron ESD 480 PEEK”,

LIGO-E1000298-v1

26. E1200994-v1, “Optical Contamination Test Results: EP-1730-1 Low Viscosity Potting

Compound”